We present ground-based SpectroCam-10 mid-infrared, MMT optical, and Spitzer Space Telescope IRS mid-infrared spectra taken 7.62, 18.75, and 19.38 yr, respectively, after the outburst of the old classical nova QU Vulpeculae (Nova Vul 1984#2). The spectra of the ejecta are dominated by forbidden line emission from neon and oxygen. Our analysis shows that neon was, at the first and last epochs respectively, more than 76 and 168 times overabundant by number with respect to hydrogen compared to the solar value. These high lower limits to the neon abundance confirm that QU VuI involved a thermonuclear runaway on an ONeMg white dwarf, and approach the yields predicted by models of the nucleosynthesis in such events.
- Infrared: stars
- Novae, cataclysmic variables
- Stars: individual (QU Vul, Nova Vul 1984 #2)